new datatype theory, supports 'draft theories' and incremental extension: add_classes, add_defsort, add_types, add_tyabbrs, add_tyabbrs_i, add_arities, add_consts, add_consts_i, add_syntax, add_syntax_i, add_trfuns, add_trrules, add_axioms, add_axioms_i, add_thyname; added merge_thy_list for multiple merges and extend-merges; added rep_theory, subthy, eq_thy, cert_axm, read_axm; changed type of axioms_of; renamed internal merge_theories to merge_thm_sgs; various internal changes of thm and theory related code;

added const_type: sg -> typ option; stamps now stored in REVERSE order; now supports 'draft signatures' and incremental extension: is_draft, add_classes (supports axclasses), add_defsort, add_types, add_tyabbrs, add_tyabbrs_i, add_arities, add_consts, add_consts_i, add_syntax, add_syntax_i, add_trfuns, add_trrules, add_name, make_draft; added const_of_class, class_of_const (for axclasses); changed the pure signature to support axclasses (added itself, TYPE); various major internal changes;

added print_sign, print_axioms: theory -> unit; replaced ["logic"] by logicS;

support for new style mixfix annotations; part of the pure syntax as mixfix (supports axclasses);

added incremental extension functions: extend_log_types, extend_type_gram, extend_const_gram, extend_consts, extend_trfuns, extend_trrules; replaced merge by merge_syntaxes; various minor internal changes;

added insort_tr, prop_tr' (for axclasses); added pure_trfuns; various minor internal changes;

replaced fix_aprop by prop_tr'; various minor internal changes;

added infix op also: 'a * ('a -> 'b) -> 'b; added set, reset, toggle: bool ref -> bool; added find_first, exists2, forall2, commas_quote, merge_rev_lists;

use_thy now uses use_string instead of creating a temporary file

added use_string: string -> unit to execute ML commands passed in a string